Blast protection window film

Blast protection window film is a tough polyester film bonded to existing glass to hold the fragments together in a blast. ArxBridge installs it across the UK in occupied buildings where replacing the windows is not practical.

• Retrofit applicationFitted to existing glazing
• Fragment retentionHolds broken glass in place
• Occupied buildingsFitted with rooms still in use
• No frame changeThe existing windows stay put

About blast protection window film

The film is a multi-layer polyester sheet, bonded to the glass with a strong adhesive and anchored at the edges. When the glass breaks under blast pressure, the film holds the fragments in a single sheet instead of letting them spray across the room. It is the standard retrofit where the threat needs a lower fragment hazard but the building cannot take new windows. The Blast range overview sets out the full rated alternatives.

Film is fitted with the building occupied: desks stay, rooms stay in use, and each window takes a fraction of the time a replacement would. It suits listed buildings, leased premises and live operational sites where a refit is out of the question.

Be clear about what film is not. It does not give the window an EXV class; only a tested glazing system earns that. It reduces the fragment hazard from the existing glass. Where the threat assessment demands a full EXV rating, the windows must be replaced with blast resistant windows.

Choosing the right rating for blast protection window film

The survey decides which windows suit film: the glass type, the frame condition and the edge detail all matter. Film bonded to a rotten frame or a loose gasket is wasted. The blast ratings guide explains the hazard scale the film is working against.

Film is hazard reduction, not a rating. It makes existing glass safer. It does not turn an untested window into an EXV rated one.

How blast protection window film works

The installer cleans the glass, cuts the film to the daylight opening and applies it to the inner face, working out every bubble. The critical step is the edge: the film is anchored to the frame with a structural bead or a mechanical batten, so the retained sheet cannot peel away under load. A film that is not edge-anchored will hold the glass together and then leave the opening as one piece.

Film thickness and ply count follow the threat: heavier films for higher demands, and multiple layers can be stacked. Solar and privacy variants combine fragment retention with heat or glare control, which often pays for the work in buildings that needed solar film anyway.

Curing takes a few days; the bond strengthens as the moisture leaves. The installation team programmes the work room by room so the building stays operational.

Pairing blast protection window film with other ratings

Fragment retention film can be combined with solar control and privacy films in one application. Where forced entry is also a concern, the answer is usually replacement rather than film: tested systems such as high-security double glazing or LPS 1270 security glazing, because film alone does not resist a sustained hand-tool attack.

On curtain walling, film is applied bay by bay and the edge anchorage is detailed against the mullions. For full facade protection see blast rated curtain walling.

Film does not change the fire rating of the glass. Where fire performance matters, the glazing must be fire rated in its own right.

Typical uses for blast protection window film

Education estates use film on classroom glazing where replacement would close the school. Healthcare sites use it on ward and corridor windows that must stay in service.

Government and defence offices use it as an interim measure while a full window replacement is programmed. Transport hubs use it on back-of-house glazing away from the main public areas.

Leased commercial buildings are a common case: the tenant cannot change the landlord’s windows, but can bond film to them. High-value retail frontages use it where the glazing line cannot be rebuilt.

What affects the cost and lead time of blast protection window film

Area is the driver: the work prices by the square metre of glass treated. Access matters next: high-level glazing needs towers or lifts, and occupied rooms need out-of-hours working.

Glass condition affects preparation: old putty, failed seals and dirty frames slow the work. The survey should catch these before the programme is fixed.

Film is the fastest blast measure to deploy: no manufacture of frames, no structural work, and no planning issues in most cases. A phased programme across a large estate can run for weeks without closing any room.

Specifying blast protection window film

1. Survey the glass. Record glass type, condition and frame detail for every window in scope.
2. Set the objective. Agree what the film must achieve: fragment retention to a stated hazard reduction.
3. Detail the edges. Specify the anchorage method at each frame type; this is where the performance lives.
4. Programme the rooms. Agree working hours and phasing with the installation team so the building stays live.
5. Plan the checks. Set the inspection cycle for the maintenance plan: edges, adhesion and damage.